If a plan administrator filed Form 5558 with the Internal Revenue Service (IRS) on or before July 31, 2011 for a calendar-year plan, the plan's Form 5500 filing deadline is extended to October 15, 2011. The plan sponsor does not need to attach a copy of Form 5558 to the annual return under EFAST2. However, the plan sponsor must keep a copy of the Form 5558 that was filed with the IRS in the plan's records.